Appendix A Modbus Communication Protocol - V&T E5-H Series User Manual

Appendix A Modbus Communication Protocol

1. Support Protocol
Support Modbus protocol, RTU format, Broadcast address 0, slave address "1−247", "248−255" for
reservation.
2. Interface mode
RS485: Asynchronous, half duplex, LSB sending priority. Low byte is after the high byte.
Inverter communication port A (RJ45) default data format: 8−N−1, 38400 bps
It is recommended to adopt EIA/TIA T568B, the lead of port A is defined as:
Lead of
communication
port A
Signal of
communication
port A
EIA/TIA T568A
EIA/TIA T568B
3. Protocol Format
ADU (Application Data Unit) check is the CRC16 check of the first three parts of ADU and obtained
through exchange of upper byte or lower byte.
If the operation request is rejected, the feedback of PDU(Protocol Data Unit) will be error code or
abnormal code. Error code equals to function code +0x80, abnormal code shows the error cause in
detail.
Examples for abnormal codes:
E5−H High Performance Universal Inverter
Attached Figure 1 RJ45 interface
1 2
+5V GND
White
Green
green orange
White
Orange
orange green
Attached Figure 2 Protocol Format
Appendix A Modbus Communication Protocol
1
8
3 4 5
485+ 485− 485+
White White
Blue
blue
White White
Blue
blue
User Manual
6 7
485− GND
White
Orange
brown
White
Green
brown
8
+5V
Brown
Brown
115